Method of making sizing material



Patented May 8, 1934 PATENT OFFICE METHOD OF MAKING SIZING MATERIALIzador J. Novak, Bridgeport, Conn., assignor to Raybestos-Manhattan,Inc., Bridgeport, Conn, a corporation of New Jersey No Drawing.Application December 19, 1931, Serial No. 582,183

1 Claim. (Cl. 9221) An object of this invention is to produce a sizingmaterial for use in treating fibrous material for use in paper,comprising a water insoluble, fatty acid soap.

5 I am aware of the fact that soluble fatty acid soaps, such as sodiumoleate, have been introduced with paper fiber, such as kraft, sulfite,et cetera, into a paper beater, and later precipitated on the fiber as,for example, aluminum l0 oleate.

Previous methods, however, have been extremely difiicult to controlbecause of excessive foaming of the soap emulsion causing the beater mixto swell enormously, making it diificult to completely acidify andprecipitate the soap, which later manifested itself by severe foaming inthe paper machine in which the beater mix was formed into a sheet. Also,the sizing and waterproofing qualities are reduced because of thepresence of unreacted soap, which is water soluble.

The present invention reduces foaming in the heater and in the papermachine to a minimum and produces a highly waterproof soap substantiallycompletely reacted to insoluble condition. The invention is capable ofeasy commercial use in large quantities and the soap may be used inlarge proportions in the stock without manufac-' turing difficulty.

The concept involved comprises the use of an emulsion of the fatty aciditself, wherein the emulsifier consists of a minimum quantity of thesame fatty acid saponified with a limited amount of alkali. Thus, thequantity of soluble soap (i. e. saponified fatty acid) is kept at aminimum, and the attendant difficulties of foaming and loss ofwaterproofing are minimized. During the reaction with aluminum sulfateor other precipitating agent the small proportion of water solublealkali soap reacts with the precipitating agent in the usual manner toform aluminum soap, for example,ialuminum oleate, and the largeproportion of unsaponified fatty acid which is present in emulsifiedform reacts directly with the aluminum sulfate to form the same aluminumsoap so that the resultant precipitate, which is the final waterproofingagent, is the same by this method as by the method where the fatty acidwas completely or largely saponified.

The production of the emulsion comprises the use of a minor fractionalpart of the alkali necessary for complete saponification of the soap incombination with large dilution with water so as to reduce thesaponification reaction to a point where complete emulsification isobtained with a minimum of saponification.

One method of preparing this sizing material is to heat about 300 poundsof water to about 125 F., dissolve completely therein about three poundsof technical caustic soda, making a solution of less than 1% alkali, andslowly add,

with stirring, about 30 pounds of oleic acid. This is then thoroughlyagitated, preferably with live steam, and the temperature is increaseduntil it has risen to about 175 F. The product is a thin cream-coloredliquid equivalent to about 10% oleic acid concentration.

The invention, of course, is not limited to agitation with steam, asmechanical agitation produces substantially the same result.

As a test, if one part of this liquid is diluted with, say ten parts ofwater by volume, the result is a cloudy liquid free from any visibleparticles. The fact that the diluted mix is cloudy instead of clear isan evidence that the fatty acid oil is emulsified rather thansaponified, as a soap solution of equal concentration would becomparatively clear. Also, the above diluted mix shows very littletendency to foam when agitated, indicating again that the proportion oftrue soap is very low.

When introduced into the beater engine, the above size mixes smoothlywith fiber without excessive foaming and may be precipitated with alumwithout difliculty. It is especially satisfactory as a Waterproofingagent for asbestos fibers, and as much as 20% by weight of aluminumoleate has been added to asbestos fiber by this method withoutdifficulty in preparation in the beater or in running on the papermachine. Both wet machines and continuous paper machines have been foundsatisfactory for running asbestos sized with high percentages ofaluminum oleate in this way. The ordinary paper fibers such as kraft,sulfite, wood pulp, asbestos, etc., are effectively sized by thismethod.

I have shown oleic acid as an example, but I may also use any equivalentfatty acids such as palmitic, stearic, linoleic, oleostearic, ormixtures of fatty acids which are liquid below the boiling point ofwater and produce sizing com positions having the specificcharacteristics of these fatty acids and later their insoluble metallicsoaps by employing the method described above.

I have also used technical caustic soda as an example, but it is to beunderstood that caustic I claim as my invention:

In the sizing of fibrous material, the method which comprisesprecipitating on the fibrous material during heating thereof aninsoluble size from an emulsion of a saponifiable free fatty aciddispersed with an emulsifier consisting of a relatively minor proportionof the same fatty acid saponified with an alkali.

IZADOR J. NOVAK.

